The invention relates to a process for treating dielectric materials during semiconductor device manufacture to control the dielectric constant of the dielectric materials. The invention also relates to methods and apparatus for forming semiconductor devices and treated dielectric materials.
Microelectronic devices such as integrated circuits, are manufactured by means of photolithographic techniques. Fabricating various structures, particularly electronic device structures, typically involves depositing at least one layer of at least one photosensitive material, typically known as a photoresist material, on a substrate. The photoresist material may then be patterned by exposing it to radiation of a certain wavelength or wavelengths to alter characteristics of the photoresist material. Typically, the radiation is from the ultraviolet range of wavelengths. The radiation causes desired photochemical reactions to occur within the photoresist.
The photochemical reactions alter the solubility characteristics of the photoresist, thereby allowing removal of certain portions of the photoresist. Selectively removing certain parts of the photoresist allows for the protection of certain areas of the substrate while exposing other areas. The remaining portions of the photoresist typically are utilized as masks or stencils for processing the underlying portions of the substrate.
An example of such a process is in the fabrication of semiconductor devices wherein, for example, layers are formed on a semiconductor substrate. Certain portions of the layers may be removed to form openings through the layers. The openings may allow diffusion of desired impurities through the openings into the semiconductor substrate. Other processes are known for forming devices on a substrate.
At times during semiconductor device manufacture, prior or subsequent to the deposition of photoresist on a substrate, other materials may be deposited on the substrate. Examples of such material include electrical conductors and electrical insulators. Electrical insulators typically include a wide variety of dielectric materials. These dielectric materials may be treated during the process of formation of the semiconductor device. Other materials may also be deposited on the dielectric materials.
For example, semiconductor devices may be formed by introducing a suitable impurity into a layer of a semiconductor to form suitably doped regions therein. In order to provide distinct P or N regions, which are necessary for the proper operation of the device, introduction of impurities should occur through only a limited portion of the substrate. Usually, this is accomplished by masking the substrate with a resist material and subsequently etching a diffusion resistant material, such as silicon dioxide or silicon nitride to a desired depth to form a protective mask to prevent diffusion of the impurities through selected areas of the substrate.
The mask in such a procedure is typically provided by forming a layer of material over the semiconductor substrate and, afterward creating a series of openings through the layer to allow the introduction of the impurities directly into the underlying surface. These openings in the mask are readily created by coating the silicon wafer with a material known as a photoresist. After forming features in the photoresist, electronic device features may be formed in or on the substrate upon which the photoresist is deposited. In addition, one or more of these deposited layers may be treated or altered prior to or after etching to maintain or enhance their performance related to the functionality of the specific semiconductor device.
Aspects of the present invention provide a process for treating a dielectric material deposited on a substrate in semiconductor device manufacturing processes. According to the method, the dielectric material is exposed to radiation.
The dielectric material is also exposed to a temperature of 20xc2x0 C. or greater. Additionally, the dielectric material is exposed to an atmosphere that includes at least one material selected from the group consisting of an amine, an amide, an aldehyde, an aromatic compound and N2.
According to other aspects, the present invention provides a device for treating a dielectric material deposited on a substrate in semiconductor device manufacturing processes. The device includes a source of radiation for exposing the dielectric material to radiation. The device also includes a heat source for exposing the dielectric material to a temperature of 20xc2x0 C. or greater. A chamber having a controlled atmosphere is used for exposing the dielectric material to an atmosphere that includes at least one material selected from the group consisting of air, an amine, an amide, an aldehyde, an aromatic compound and N2.
Additional aspects of the present invention provide a semiconductor device prepared according to a process that includes the above-described process for treating a dielectric material.
Also, aspects of the present invention provide a method for preparing a semiconductor device that includes the above process for treating a dielectric material.
Further aspects of the present invention provide a treated dielectric material that has been treated according to the above-discussed process for treating a dielectric material.
Still other objects and advantages of the present invention will become readily apparent by those skilled in the art from the following detailed description, wherein it is shown and described only the preferred embodiments of the invention, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.